Platelet Function in Patients with Diabetes Mellitus: From a Theoretical to a Practical Perspective

Patients with diabetes mellitus have an increased prevalence of vascular disease. Pathologic thrombosis associated with atherosclerotic plaque rupture is a major cause of morbidity and mortality. Platelets are intimately involved in the initiation and propagation of thrombosis. Evidence suggests that platelets from patients with type 2 diabetes have increased reactivity and baseline activation compared to healthy controls. We review the pathophysiology of platelet hyperreactivity in DM patients and its implications in clinical practice, with particular focus on acute coronary syndromes, percutaneous coronary intervention, and novel antiplatelet agents

1004-57 Regional Left Ventricular Function by Intraventricular Ultrasound in Patients with Myocardial Infarction

Regional left ventricular (LV) dysfunction induced by ischemia/infarction is accompanied by increased end-systolic stress because the ischemic LV wall is unable to generate enough tension to contribute effectively to systole. To explore the possibility of assessing regional LV dysfunction as changes in LV wall stress we performed intraventricular echocardiography in 10 patients with a 6.2 french/12.5MHZ catheter at the time of cardiac catheterization. Cross-sectional images obtained at the level of the papillary muscles were analyzed by computer aided system to assess left ventricular wall thickness and radius of curvature (RC) in 16 equi-angular segments. End-systolic segmental endocardial radius of curvature divided by LV wall thickness obtained as segment area divided by the average of endo and epicardial arc lengths was utilized as an index of regional LV performance proportional to segmental LV wall stress. Percent wall thickening (WT%) was reduced (20.7±14.5%) in the territory perfused by the stenosed artery determined at catheterization, when compared with WT% obtained from territory perfused by normal coronaries (34.4±15.8%, p<0.05). In addition, systolic wall thickening was inversely related to the ratio of RC to WT at end-systole (r=0.75, %WT=65.5 – 21.4 (RCIWT), p<0.05) reflecting regional systolic dysfunction with increased circumferential end-systolic wall stress in those regions. In conclusion, intraventricular echocardiography correctly detects regional left ventricular dysfunction and its geometric consequences to local LV performance induced by ischemic myocardial damage. This technique may play an important role in monitoring myocardial injury by ischemia during invasive interventional procedures

Impact of COVID-19 Pandemic on TAVR Activity: A Worldwide Registry

Background: The COVID-19 pandemic had a considerable impact on the provision of structural heart intervention worldwide. Our objectives were: 1) to assess the impact of the COVID-19 pandemic on transcatheter aortic valve replacement (TAVR) activity globally; and 2) to determine the differences in the impact according to geographic region and the demographic, development, and economic status of diverse international health care systems. Methods: We developed a multinational registry of global TAVR activity and invited individual TAVR sites to submit TAVR implant data before and during the COVID-19 pandemic. Specifically, the number of TAVR procedures performed monthly from January 2019 to December 2021 was collected. The adaptive measures to maintain TAVR activity by each site were recorded, as was a variety of indices relating to type of health care system and national economic indices. The primary subject of interest was the impact on TAVR activity during each of the pandemic waves (2020 and 2021) compared with the same period pre–COVID-19 (2019). Results: Data were received from 130 centers from 61 countries, with 14 subcontinents and 5 continents participating in the study. Overall, TAVR activity increased by 16.7% (2,337 procedures) between 2018 and 2019 (ie, before the pandemic), but between 2019 and 2020 (ie, first year of the pandemic), there was no significant growth (–0.1%; –10 procedures). In contrast, activity again increased by 18.9% (3,085 procedures) between 2020 and 2021 (ie, second year of the pandemic). During the first pandemic wave, there was a reduction of 18.9% (945 procedures) in TAVR activity among participating sites, while during the second and third waves, there was an increase of 6.7% (489 procedures) and 15.9% (1,042 procedures), respectively. Further analysis and results of this study are ongoing and will be available at the time of the congress. Conclusion: The COVID-19 pandemic initially led to a reduction in the number of patients undergoing TAVR worldwide, although health care systems subsequently adapted, and the number of TAVR recipients continued to grow in subsequent COVID-19 pandemic waves. Categories: STRUCTURAL: Valvular Disease: Aorti

Diagnosis and Management of Valvular Aortic Stenosis

Valvular aortic stenosis (AS) is a progressive disease that affects 2% of the population aged 65 years or older. The major cause of valvular AS in adults is calcification and fibrosis of a previously normal tricuspid valve or a congenital bicuspid valve, with rheumatic AS being rare in the United States. Once established, the rate of progression of valvular AS is quite variable and impossible to predict for any particular patient. Symptoms of AS are generally insidious at onset, though development of any of the three cardinal symptoms of angina, syncope, or heart failure portends a poor prognosis. Management of symptomatic AS remains primarily surgical, though transcatheter aortic valve replacement (TAVR) is becoming an accepted alternative to surgical aortic valve replacement (SAVR) for patients at high or prohibitive operative risk

Prospective motion correction of X-ray images for coronary interventions

Abstract—A method for prospective motion correction of X-ray imaging of the heart is presented. A Qh C � coronary model is reconstructed from a biplane coronary angiogram obtained during free breathing. The deformation field is parameterized by cardiac and respiratory phase, which enables the estimation of the state of the arteries at any phase of the cardiac-respiratory cycle. The motion of the three-dimensional (3-D) coronary model is projected onto the image planes and used to compute a dewarping function for motion correcting the images. The use of a 3-D coronary model facilitates motion correction of images acquired with the X-ray system at arbitrary orientations. The performance of the algorithm was measured by tracking the motion of selected left coronary landmarks using a template matching cross-correlation. In three patients, we motion corrected the same images used to construct their Qh C � coronary model. In this best case scenario, the algorithm reduced the motion of the landmarks by 84%–85%, from mean RMS displacements of 12.8–14.6 pixels to 2.1–2.2 pixels. Prospective motion correction was tested in five patients by building the coronary model from one dataset, and correcting a second dataset. The patient’s cardiac and respiratory phase are monitored and used to calculate the appropriate correction parameters. The results showed a 48%–63 % reduction in the motion of the landmarks, from a mean RMS displacement of 11.5–13.6 pixels to 4.4–7.1 pixels. Index Terms—Chest imaging, motion compensation, X-ray angiography. I

Patent Foramen Ovale in Patients with Sickle Cell Disease and Stroke: Case Presentations and Review of the Literature

Although individuals with sickle cell disease (SCD) are at increased risk for stroke, the underlying pathophysiology is incompletely understood. Intracardiac shunting via a patent foramen ovale (PFO) is associated with cryptogenic stroke in individuals without SCD. Recent evidence suggests that PFOs are associated with stroke in children with SCD, although the role of PFOs in adults with stroke and SCD is unknown. Here, we report 2 young adults with SCD, stroke, and PFOs. The first patient had hemoglobin SC and presented with a transient ischemic attack and a subsequent ischemic stroke. There was no evidence of cerebral vascular disease on imaging studies and the PFO was closed. The second patient had hemoglobin SS and two acute ischemic strokes. She had cerebral vascular disease with moyamoya in addition to a peripheral deep venous thrombosis (DVT). Chronic transfusion therapy was recommended, and the DVT was managed with warfarin. The PFO was not closed, and the patients' neurologic symptoms were stabilized. We review the literature on PFOs and stroke in SCD. Our cases and the literature review illustrate the dire need for further research to evaluate PFO as a potential risk factor for stroke in adults with SCD

METHODS Computer Models of Coronary Arteries

• Contrast opacified coronary angiograms provide high temporal and spatial resolution images used to diagnose coronary stenoses. (Figure 1A) • Interventional therapies are targeted “blindly”; the target location is only visible when contrast is injected. (Figure 1B) • Interventional navigation is complicated by physiologic motion that displaces the catheter in the fluoroscopic images. OBJECTIVE • To develop a method for stabilizing motion in x-ray images. • To predict and compensate for the cardiac and respiratory motions of the heart. A B Figure 1 Stenoses are visualized in a contrast opacified coronary angiogram (A). PTCA is targeted using images lacking vessel contrast (B). The cardiologist has to compensate mentally for the cardiac and breathing motion that continuously displaces the catheter in these images